CN102519973A - Method for detecting lip defect of PET bottle or bottle parison - Google Patents

Abstract

The invention discloses a method for detecting the lip defect of a PET bottle or a bottle parison. According to the invention, a lip annular zone image is acquired; the image is transversally expanded at a tangential point; gradients are calculated on a transversal direction; a radial sum of the transversal gradients are adopted as characteristic parameters, such that the lip defect of the PET bottle or the bottle parison can be determined and analyzed. The method is simple, and can be used for detecting problems such as bottle lip knocking, bottle lip damages and cracks. With the method, detection precision is improved, and error rejection rate can be greatly reduced.

Description

A kind of method that detects PET bottle or bottle embryo bottle mouth defect

Technical field

The invention belongs to the mechanical vision inspection technology field, especially relate to the method for a kind of PET of detection bottle or bottle embryo bottle mouth defect.

Background technology

At present, the manufacturing process of PET bottle all is to carry out embryo earlier, through bottle blowing machine it is shaped then, need check in process of production whether the upper surface of bottleneck exists breakage, prevents after capping, to leak gas, and produces unacceptable product.The detection method of this respect seldom; Because rotational line speed is very fast; And the folder bottle system is not steady especially, and the lightness of taking is also inhomogeneous, and general method is difficult to stable detection and goes out different defects; Also be prone to Lou rejecting and mistake and reject phenomenon, press for the detection that a kind of good detection method is accomplished this product.

Summary of the invention

The objective of the invention is: the method that a kind of method is easy, accuracy of detection is high detection PET bottle or bottle embryo bottle mouth defect are provided.

Technical scheme of the present invention is: the method that detects the bottle mouth defect of PET bottle or bottle embryo may further comprise the steps:

(1) gather PET bottle or bottle embryo bottleneck image, and the input computer system;

(2) extraction flask choma area image, with image from the point of contact horizontal spreading, ask gradient in a lateral direction;

(3) select the Sobel wave filter to image filtering, calculate transverse gradients;

(4) transverse gradients of trying to achieve is radially being sued for peace and assignment is given original matrix;

(5) according to transverse gradients radially with as characteristic quantity, discriminatory analysis goes out the bottle mouth defect of PET bottle or bottle embryo.

The invention has the beneficial effects as follows: this method has very succinctly effectively solved the problem of PET bottle or the detection of bottle embryo bottleneck; On high-speed automated production line; To pet container carry out before the bottle blowing or bottle blowing after bottleneck detect and handle; Can detect problems such as bottleneck is damaged, bottleneck breakage, crackle, when improving accuracy of detection, also greatly reduce mistake and reject.

Description of drawings

Fig. 1 is that synoptic diagram is used in detection of the present invention.

Embodiment

The method that the present invention detects PET bottle or bottle embryo bottle mouth defect may further comprise the steps:

Step (one): gather PET bottle or bottle embryo bottleneck image, and the input computer system.

Step (two): extraction flask choma area image, ask gradient in a lateral direction, horizontal direction is the tangential direction of corresponding original image, is about to bottle germ ring border circular areas image and seeks a point of contact, the horizontal spreading from the point of contact is asked gradient in a lateral direction.

Step (three): select the Sobel wave filter to image filtering, calculate transverse gradients.Wave filter in the use formula (1-1) that the calculating of transverse gradients can be similar to carries out filtering to the bottle germ ring zone after extracting and obtains.

Formula (1-1):

During as ; Obtain the Prewitt wave filter, it is vertically carrying out a mean filter processing.During as

; Obtained the Frei wave filter, its shortcoming is to need Floating-point Computation.During as

; Obtained the Sobel wave filter, it is similar to the level and smooth processing of Gauss one of vertical execution.In above three wave filters because the Sobel wave filter has used best smoothing filter, can effectively suppress noise, so its result who returns is best, thus select the Sobel wave filter to bottle germ ring image filtering to calculate transverse gradients.

Step (four): the transverse gradients of trying to achieve is radially being sued for peace and assignment is given original matrix.In the transverse gradients of trying to achieve, the position that peak value occurs is and collapses the damage fault location, and various disturbing factors are seeming more at random in the radial direction, but rule is apparent in view on tangential direction.In order to eliminate the even The noise of the brightness disproportionation that causes owing to reasons such as illumination, radially the gradient of trying to achieve is being sued for peace and assignment is given original matrix.

Step (five): radially and as characteristic quantity detect bottle mouth defect according to transverse gradients.

Fig. 1 is that synoptic diagram is used in detection of the present invention; Be the Grad after radially suing for peace; As can be seen from the figure; In that to decrease the zone very obvious with the difference of normal region to collapsing after the gradient summation in the radial direction, collapse decrease regional gradient and absolute value about 4000, and the value of normal region is less than 1000.According to transverse gradients radially and as the characteristic quantity discriminatory analysis go out the bottle mouth defect of PET bottle or bottle embryo, accuracy of detection is high, false drop rate is low.

Claims (1)

1. a method that detects the bottle mouth defect of PET bottle or bottle embryo is characterized in that, may further comprise the steps:

(1) gather PET bottle or bottle embryo bottleneck image, and the input computer system;

(2) extraction flask choma area image, with image from the point of contact horizontal spreading, ask gradient in a lateral direction;

(3) select the Sobel wave filter to image filtering, calculate transverse gradients;

(4) transverse gradients of trying to achieve is radially being sued for peace and assignment is given original matrix;

(5) according to transverse gradients radially with as characteristic quantity, discriminatory analysis goes out the bottle mouth defect of PET bottle or bottle embryo.

Images